Functions useful to write assertions, especially preconditions

Classes
		__builtin__.object shall_raise   class shall_raise(__builtin__.object)       Methods defined here: __call__(self, *args, **kwds) __init__(self, func, *exceptions) Data descriptors defined here: __dict__ dictionary for instance variables (if defined) __weakref__ list of weak references to the object (if defined)

Functions
		is_numeric(x) is_string(s)